Hello, if you have the time, could you explain how hair lines work?? specifically on men because I am struggling :-(

Well, I can give you some tips based on how I do it. Your mileage may vary.

I mainly figure out where my dudes’ hairlines are supposed to be based on the physical landmarks of the head. Here’s a generic head I drew up that highlights those parts. It’s not realistically accurate since these are TF2-ish proportions, but it does involve knowledge of actual anatomy, which isn’t as scary as it sounds.

1-3 are self-explanatory. 4 is that slight bony ridge around that little depressed area behind your forehead on the sides. 5 is the bump of the base of your skull where it meets your neck muscle.

Also, notice where things line up, since these are clues to help you lock things in place and keep facial features from floating around too much. For example, the top of the ear generally lines up with the eyeline and the bottom with the mouth. There are lots of little tricks like that.

And here’s a generic hairline based on these landmarks.

Of course, reference is also going to help you out a bunch here. The above approximation is just meant to give a basic idea of where a hairline would be. Like fingerprints, everyone’s hairline is unique. Depending on your character, you should feel free to mix it up!

These are just a few slight variations, to give you an idea of what I mean: rounded, pointy, and receding. Once I have my hairline roughed in, I pick where the hair part is (if there is one) and sketch in the hair, following the natural growth pattern of hair.

You can get nearly infinite variations! Get wacky with it! And there’s no one 100% correct way to draw a hairline (or anything else, for that matter) so don’t get too hung up on not doing it wrong. Practice until you’re comfortable, and you’ll be winging it in no time.